Pub Date : 2022-06-24DOI: 10.17159/caj/2022/32/1.13477
B. Wernecke, John-Rob Pool
NA
纳
{"title":"Are nature-based solutions a missing link in air quality management in South African cities?","authors":"B. Wernecke, John-Rob Pool","doi":"10.17159/caj/2022/32/1.13477","DOIUrl":"https://doi.org/10.17159/caj/2022/32/1.13477","url":null,"abstract":"<jats:p>NA</jats:p>","PeriodicalId":37511,"journal":{"name":"Clean Air Journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48442275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.17159/caj/2022/32/1.12546
Cynthia N. Sitati, C. Oludhe, L. Oyake, A. Mbandi
Traffic congestion significantly contributes to climate change due to the emissions of Greenhouse Gases (GHGs) such as Carbon Dioxide (CO2), Nitrous Oxide (N2O), and Ozone (O3). Rapid urbanization and poor planning coupled with increased motorization and fragmented public transport system in cities such as Nairobi have led to increased vehicular emissions especially during heavy traffic along the various roads and within the Central Business District (CBD). To reduce GHG emissions in the urban transport sector, institutional coordination and relevant policy tools must be considered. This study aimed at estimating CO2 emissions from different vehicles during traffic congestion, using Uhuru Highway as a case study. The relationship between traffic congestion and CO2 emissions was analyzed using qualitative and quantitative methods, through a bottom-up approach. Questionnaires were administered to get individual vehicle characteristics and opinions on the best actions for the reduction of CO2 emissions along Uhuru Highway in Nairobi. The Average Annual Daily Traffic (AADT) for different vehicles from 2014 to 2019 was used to estimate the CO2 emissions. Results showed that private cars predominate over other vehicle types, contributing to 73% of the total CO2 emissions in Nairobi (CBD). Private cars are the highest contributor of CO2 emissions with a total of 25.3 million Carbo dioxide equivalent (gCO2e), between 2014 and 2019. In comparison, Public Service Vehicles, commonly referred to as Matatus emitted 6.89 million gCO2e, Light Commercial Vehicles (1.82 million gCO2e), Heavy Goods Vehicles (251,683 gCO2e), and motorcycles (181,054 gCO2e). To minimize CO2 emissions, the study recommended the enforcement of strong mobility policies to control the high motorization rate. One of these policies is the prioritization of the development of the mass public transport systems to achieve the potential health, economic and environmental gains within the CBD.
{"title":"A street-level assessment of greenhouse gas emissions associated with traffic congestion in the city of Nairobi, Kenya","authors":"Cynthia N. Sitati, C. Oludhe, L. Oyake, A. Mbandi","doi":"10.17159/caj/2022/32/1.12546","DOIUrl":"https://doi.org/10.17159/caj/2022/32/1.12546","url":null,"abstract":"Traffic congestion significantly contributes to climate change due to the emissions of Greenhouse Gases (GHGs) such as Carbon Dioxide (CO2), Nitrous Oxide (N2O), and Ozone (O3). Rapid urbanization and poor planning coupled with increased motorization and fragmented public transport system in cities such as Nairobi have led to increased vehicular emissions especially during heavy traffic along the various roads and within the Central Business District (CBD). To reduce GHG emissions in the urban transport sector, institutional coordination and relevant policy tools must be considered. This study aimed at estimating CO2 emissions from different vehicles during traffic congestion, using Uhuru Highway as a case study. The relationship between traffic congestion and CO2 emissions was analyzed using qualitative and quantitative methods, through a bottom-up approach. Questionnaires were administered to get individual vehicle characteristics and opinions on the best actions for the reduction of CO2 emissions along Uhuru Highway in Nairobi. The Average Annual Daily Traffic (AADT) for different vehicles from 2014 to 2019 was used to estimate the CO2 emissions. Results showed that private cars predominate over other vehicle types, contributing to 73% of the total CO2 emissions in Nairobi (CBD). Private cars are the highest contributor of CO2 emissions with a total of 25.3 million Carbo dioxide equivalent (gCO2e), between 2014 and 2019. In comparison, Public Service Vehicles, commonly referred to as Matatus emitted 6.89 million gCO2e, Light Commercial Vehicles (1.82 million gCO2e), Heavy Goods Vehicles (251,683 gCO2e), and motorcycles (181,054 gCO2e). To minimize CO2 emissions, the study recommended the enforcement of strong mobility policies to control the high motorization rate. One of these policies is the prioritization of the development of the mass public transport systems to achieve the potential health, economic and environmental gains within the CBD.","PeriodicalId":37511,"journal":{"name":"Clean Air Journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42096078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.17159/caj/2022/32/1.13081
M. Bieri, J. D. du Toit, G. Feig, N. Maluta, B. Mantlana, M. Mateyisi, G. Midgley, S. Mutanga, G. Von Maltitz, C. Brümmer
There is a lack of long-term greenhouse gas (GHG) measurement infrastructures in Africa. This limits our understanding of the temporal dynamics of the biosphere-atmosphere exchange of carbon in response to climate change. Where relevant infrastructures have been established in externally funded research projects, they have often not been successfully transferred to local institutions at project termination, nor maintained in the long term. This leads to loss of capacity and continuity in primary data. We describe a collaborative approach where eddy-covariance (EC) towers for continuous long-term observation of carbon dioxide and energy fluxes were constructed under two consecutive German-funded research projects and designed to complement existing South African infrastructures. They will be transferred to partner institutions at project termination, supported by deliberate capacity building actions for long term sustainability. Joint activities were implemented to i) strengthen technical expertise for infrastructure maintenance, ii) introduce new generation of academic scientists to the topic, iii) co-develop a training concept to enhance local capacity to continue teaching the topic, iv) improve the uptake and use of data by the research community, v) improve data use and access by stakeholders, and vi) facilitate knowledge exchange between institutions. Co-designed activities included training, apprenticeships and knowledge exchange, student exchange, co-supervision, and public outreach. Following a similar model in international research projects could significantly benefit 1) national capacity for emission inventories, 2) development of long-term GHG observation networks, and 3) the global scientific community via improved availability of data. While we specifically focus on a network of GHG observations, the principles are applicable for the infrastructure to observe other surface/atmosphere exchange processes or other long term observational infrastructure.
{"title":"Integrating project-based infrastructures with long-term greenhouse gas observations in Africa","authors":"M. Bieri, J. D. du Toit, G. Feig, N. Maluta, B. Mantlana, M. Mateyisi, G. Midgley, S. Mutanga, G. Von Maltitz, C. Brümmer","doi":"10.17159/caj/2022/32/1.13081","DOIUrl":"https://doi.org/10.17159/caj/2022/32/1.13081","url":null,"abstract":"There is a lack of long-term greenhouse gas (GHG) measurement infrastructures in Africa. This limits our understanding of the temporal dynamics of the biosphere-atmosphere exchange of carbon in response to climate change. Where relevant infrastructures have been established in externally funded research projects, they have often not been successfully transferred to local institutions at project termination, nor maintained in the long term. This leads to loss of capacity and continuity in primary data. We describe a collaborative approach where eddy-covariance (EC) towers for continuous long-term observation of carbon dioxide and energy fluxes were constructed under two consecutive German-funded research projects and designed to complement existing South African infrastructures. They will be transferred to partner institutions at project termination, supported by deliberate capacity building actions for long term sustainability. Joint activities were implemented to i) strengthen technical expertise for infrastructure maintenance, ii) introduce new generation of academic scientists to the topic, iii) co-develop a training concept to enhance local capacity to continue teaching the topic, iv) improve the uptake and use of data by the research community, v) improve data use and access by stakeholders, and vi) facilitate knowledge exchange between institutions. Co-designed activities included training, apprenticeships and knowledge exchange, student exchange, co-supervision, and public outreach. Following a similar model in international research projects could significantly benefit 1) national capacity for emission inventories, 2) development of long-term GHG observation networks, and 3) the global scientific community via improved availability of data. While we specifically focus on a network of GHG observations, the principles are applicable for the infrastructure to observe other surface/atmosphere exchange processes or other long term observational infrastructure.","PeriodicalId":37511,"journal":{"name":"Clean Air Journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49054503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.17159/caj/2022/32/1.12508
C. Pauw, H. M. Murray, Marcus A. Howard
Meaningful proportions of households on the South African Highveld regularly use energy carriers that result in the emission of significant quantities of particulate and gaseous pollutants. Dirty fuels are mostly used by lower-income households, with the exception of recreational wood use that is also prevalent in higher-income households. The dirty fuel use patterns and trends observed on the Highveld are the result of the unique combination of the utility, accessibility, affordability, availability, and desirability of the energy carriers and equipment, climatological factors, markets and infrastructure, as well as the inertia of historic energy use patterns. There are no systematic reviews and prognosis of the use of dirty fuels by low-income households on the South African Highveld that consider critical recent events such as the Covid pandemic and emerging dynamics such as the just transition movement. In this article we will use a literature review as well as our own research to describe dirty fuel use by low-income households on the Highveld, paying specific attention to changes over time. We will attempt to describe what is being used, who the users are, and for which utilities fuels are being used. From these descriptions, specific patterns emerge that shed light on possible avenues and prospects for ending dirty fuel use on the Highveld.
{"title":"use of dirty fuels by low-income households on the South African Highveld","authors":"C. Pauw, H. M. Murray, Marcus A. Howard","doi":"10.17159/caj/2022/32/1.12508","DOIUrl":"https://doi.org/10.17159/caj/2022/32/1.12508","url":null,"abstract":"Meaningful proportions of households on the South African Highveld regularly use energy carriers that result in the emission of significant quantities of particulate and gaseous pollutants. Dirty fuels are mostly used by lower-income households, with the exception of recreational wood use that is also prevalent in higher-income households. The dirty fuel use patterns and trends observed on the Highveld are the result of the unique combination of the utility, accessibility, affordability, availability, and desirability of the energy carriers and equipment, climatological factors, markets and infrastructure, as well as the inertia of historic energy use patterns. There are no systematic reviews and prognosis of the use of dirty fuels by low-income households on the South African Highveld that consider critical recent events such as the Covid pandemic and emerging dynamics such as the just transition movement. In this article we will use a literature review as well as our own research to describe dirty fuel use by low-income households on the Highveld, paying specific attention to changes over time. We will attempt to describe what is being used, who the users are, and for which utilities fuels are being used. From these descriptions, specific patterns emerge that shed light on possible avenues and prospects for ending dirty fuel use on the Highveld.","PeriodicalId":37511,"journal":{"name":"Clean Air Journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42555372","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.17159/caj/2022/32/1.12505
K. Altieri, Jessica Burger, B. Language, S. Piketh
In South Africa, the Highveld region and the Johannesburg-Pretoria megacity are known as global NOx (NOx = NO + NO2) “hotspots” identified by satellite-based instruments. The ultimate sink for atmospheric NOx is conversion to aerosol nitrate. However, measurements of aerosol nitrate concentrations do not provide information on which NOx sources served as nitrate precursors at that location. This complicates efforts to reduce concentrations of particulate matter (PM) in these air quality priority areas. Here, we measured the nitrogen stable isotopic composition of nitrate from daily wintertime collections of coarse mode PM2.5-10 (PM ≤ 10 and >2.5 µm in diameter) at three air quality monitoring stations located in the Vaal Triangle Air-Shed Priority Area (VTAPA). The overall aim of this case study was to evaluate the use of the distinct stable isotopic signatures of various NOx sources to identify their relative contribution to aerosol nitrate across the Highveld. The nitrogen isotopic ratios of aerosol nitrate were similar across the three sites, with greater day-to-day variability than site to site variability. Air mass history was the main driver of the variability in the nitrogen isotopic ratios of aerosol nitrate, with significantly higher isotopic ratios observed for air masses originating from the southwest. Using an isotope mixing model we determined that NOx from coal-burning is the dominant contributor to aerosol nitrate (66%), followed by biomass burning (16%), vehicles (12%), and soil emissions (6%).
在南非，Highveld地区和约翰内斯堡-比勒陀利亚特大城市被卫星仪器确定为全球氮氧化物(NOx = NO + NO2)“热点”。大气中氮氧化物的最终汇是转化为气溶胶硝酸盐。然而，对气溶胶硝酸盐浓度的测量并不能提供有关哪些氮氧化物来源在该地点充当硝酸盐前体的信息。这使得在这些空气质量重点地区降低颗粒物(PM)浓度的努力变得复杂。在这里，我们测量了位于瓦尔三角空气棚优先区(VTAPA)的三个空气质量监测站冬季日常收集的粗态PM2.5-10 (PM≤10和>直径2.5µm)中硝酸盐的氮稳定同位素组成。本案例研究的总体目的是评估各种氮氧化物来源的不同稳定同位素特征的使用情况，以确定它们对整个高原气溶胶硝酸盐的相对贡献。气溶胶硝酸盐的氮同位素比率在三个站点之间相似，其日变异性大于站点间变异性。气团历史是气溶胶硝酸盐氮同位素比率变化的主要驱动因素，来自西南的气团观测到的同位素比率明显较高。使用同位素混合模型，我们确定燃煤产生的氮氧化物是气溶胶硝酸盐的主要来源(66%)，其次是生物质燃烧(16%)、车辆(12%)和土壤排放(6%)。
{"title":"A case study in the wintertime Vaal Triangle Air-Shed Priority Area on the utility of the nitrogen stable isotopic composition of aerosol nitrate to identify NOx sources","authors":"K. Altieri, Jessica Burger, B. Language, S. Piketh","doi":"10.17159/caj/2022/32/1.12505","DOIUrl":"https://doi.org/10.17159/caj/2022/32/1.12505","url":null,"abstract":"In South Africa, the Highveld region and the Johannesburg-Pretoria megacity are known as global NOx (NOx = NO + NO2) “hotspots” identified by satellite-based instruments. The ultimate sink for atmospheric NOx is conversion to aerosol nitrate. However, measurements of aerosol nitrate concentrations do not provide information on which NOx sources served as nitrate precursors at that location. This complicates efforts to reduce concentrations of particulate matter (PM) in these air quality priority areas. Here, we measured the nitrogen stable isotopic composition of nitrate from daily wintertime collections of coarse mode PM2.5-10 (PM ≤ 10 and >2.5 µm in diameter) at three air quality monitoring stations located in the Vaal Triangle Air-Shed Priority Area (VTAPA). The overall aim of this case study was to evaluate the use of the distinct stable isotopic signatures of various NOx sources to identify their relative contribution to aerosol nitrate across the Highveld. The nitrogen isotopic ratios of aerosol nitrate were similar across the three sites, with greater day-to-day variability than site to site variability. Air mass history was the main driver of the variability in the nitrogen isotopic ratios of aerosol nitrate, with significantly higher isotopic ratios observed for air masses originating from the southwest. Using an isotope mixing model we determined that NOx from coal-burning is the dominant contributor to aerosol nitrate (66%), followed by biomass burning (16%), vehicles (12%), and soil emissions (6%).","PeriodicalId":37511,"journal":{"name":"Clean Air Journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44461814","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.17159/caj/2022/32/1.10906
P. Green, Deo Okure, Priscilla Adong, Richard Sserunjogi, Engineer Bainomugisha
Air pollution is considered a major public health risk globally, and the global South including sub-Saharan Africa face particular health risks, but there is limited data to quantify the level of pollution for different air quality contexts. The COVID-19 lockdown measures led to reduced human activities, and provided a unique opportunity to explore the impacts of reduced activities on urban air quality. This paper utilises calibrated data from a low-cost sensor network to explore insights from the diverse ambient air quality profile for four urban locations in Greater Kampala, Uganda before and during lockdown from March 31 to May 5 2020, highlighting the uniqueness of air pollution profiles in a sub-Saharan African setting. All locations saw year to year improvements in 24-hour mean PM2.5 between 9 μg/m3 and 25 μg/m3 and correlated well with reduction in traffic (up to approx. 80%) and commercial activities. The greatest improvement was observed in locations close to major transport routes in densely populated residential areas between 8:00 pm and 5:00 am. This suggests that the reduction in localised pollution sources such as nocturnal polluting activities including traffic and outdoor street cooking characteristic of fast-growing cities in developing countries, coupled with meteorological effects led to amplified reductions that continued well into the night, although meteorological effects are more generalised. Blanket policy initiatives targeting peak pollution hours could be adopted across all locations, while transport sector regulation could be very effective for pollution management. Likewise, because of the clustered and diffuse nature of pollution, community driven initiatives could be feasible for long-term mitigation.
{"title":"Exploring PM2.5 variations from a low-cost sensor network in Greater Kampala, during COVID-19 imposed lockdown restrictions: Lessons for policy","authors":"P. Green, Deo Okure, Priscilla Adong, Richard Sserunjogi, Engineer Bainomugisha","doi":"10.17159/caj/2022/32/1.10906","DOIUrl":"https://doi.org/10.17159/caj/2022/32/1.10906","url":null,"abstract":"Air pollution is considered a major public health risk globally, and the global South including sub-Saharan Africa face particular health risks, but there is limited data to quantify the level of pollution for different air quality contexts. The COVID-19 lockdown measures led to reduced human activities, and provided a unique opportunity to explore the impacts of reduced activities on urban air quality. This paper utilises calibrated data from a low-cost sensor network to explore insights from the diverse ambient air quality profile for four urban locations in Greater Kampala, Uganda before and during lockdown from March 31 to May 5 2020, highlighting the uniqueness of air pollution profiles in a sub-Saharan African setting. All locations saw year to year improvements in 24-hour mean PM2.5 between 9 μg/m3 and 25 μg/m3 and correlated well with reduction in traffic (up to approx. 80%) and commercial activities.\u0000The greatest improvement was observed in locations close to major transport routes in densely populated residential areas between 8:00 pm and 5:00 am. This suggests that the reduction in localised pollution sources such as nocturnal polluting activities including traffic and outdoor street cooking characteristic of fast-growing cities in developing countries, coupled with meteorological effects led to amplified reductions that continued well into the night, although meteorological effects are more generalised. Blanket policy initiatives targeting peak pollution hours could be adopted across all locations, while transport sector regulation could be very effective for pollution management. Likewise, because of the clustered and diffuse nature of pollution, community driven initiatives could be feasible for long-term mitigation.","PeriodicalId":37511,"journal":{"name":"Clean Air Journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45641263","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.17159/caj/2022/32/1.13242
R. Kai, M. Scholes, S. Piketh, R. Scholes
Anthropogenic emissions from industry, biomass burning and traffic are significant contributors to the atmospheric loading of nitrogen dioxide on the South African Highveld. These sources are dispersed across the region and emit nitrogen oxides (NO and NO2)into the atmosphere at different elevations above the earth's surface. Additionally, atmospheric stability in the form of surface andelevated inversions decreases the dispersion of air pollutants and stratifies pollutants into distinctive layers above the surface. Thisstudy explores the Highveld near-surface nitrogen dioxide concentrations obtained using the ground-based Pandora-2s monitoringsystem. The Pandora-2s instrument retrieves surface NO2 levels from clear sky measurements using a fully parameterised algorithm.We present the first near-surface concentration measurements of atmospheric NO2 at Wakkerstroom, a site between Volksrust andAmersfoort, downstream of major source conglomerates, the Majuba power station and other industries. These data are exploredin the presence and context of potential background NO2 concentrations in the area derived from other ground-based sensors. Thequasicontinuous data show elevated surface NO2 levels in week 37 (September) of 2020 (7.3 ± 5.7 ppb), while the lowest levels wereobserved in week 15 (April) of 2020 (0.2 ± 0.04 ppb). The elevated surface NO2 levels are driven by dominant emission sources andtransport trajectories, while the accuracy in the measurements is based on the high temporal resolution of the ground-based Pandora2s instrument.
{"title":"Analysis of the first surface nitrogen dioxide concentration observations over the South African Highveld derived from the Pandora-2s instrument","authors":"R. Kai, M. Scholes, S. Piketh, R. Scholes","doi":"10.17159/caj/2022/32/1.13242","DOIUrl":"https://doi.org/10.17159/caj/2022/32/1.13242","url":null,"abstract":"Anthropogenic emissions from industry, biomass burning and traffic are significant contributors to the atmospheric loading of nitrogen dioxide on the South African Highveld. These sources are dispersed across the region and emit nitrogen oxides (NO and NO2)into the atmosphere at different elevations above the earth's surface. Additionally, atmospheric stability in the form of surface andelevated inversions decreases the dispersion of air pollutants and stratifies pollutants into distinctive layers above the surface. Thisstudy explores the Highveld near-surface nitrogen dioxide concentrations obtained using the ground-based Pandora-2s monitoringsystem. The Pandora-2s instrument retrieves surface NO2 levels from clear sky measurements using a fully parameterised algorithm.We present the first near-surface concentration measurements of atmospheric NO2 at Wakkerstroom, a site between Volksrust andAmersfoort, downstream of major source conglomerates, the Majuba power station and other industries. These data are exploredin the presence and context of potential background NO2 concentrations in the area derived from other ground-based sensors. Thequasicontinuous data show elevated surface NO2 levels in week 37 (September) of 2020 (7.3 ± 5.7 ppb), while the lowest levels wereobserved in week 15 (April) of 2020 (0.2 ± 0.04 ppb). The elevated surface NO2 levels are driven by dominant emission sources andtransport trajectories, while the accuracy in the measurements is based on the high temporal resolution of the ground-based Pandora2s instrument.","PeriodicalId":37511,"journal":{"name":"Clean Air Journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48568747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.17159/caj/2022/32/1.11389
Ishika Nag
Air pollution kills an estimated seven million people worldwide every year. The data from the World Health Organization (WHO) shows that almost all the global population (99%) breathe air that exceeds WHO guideline limits. The growing population and urbanization such as in Africa, which has the fastest growing population, may lead to substantial worsening of the air quality. Urbanization is also a powerful driver of the epidemiologic transition from traditional threats like infectious diseases and malnutrition to chronic, non-communicable diseases. Particulate matter less than 2.5 microns in size, PM2.5, is the leading contributor to air pollution which results in such diseases like chronic obstructive pulmonary disease (COPD), bronchitis, and lung cancer. Recent studies have shown a strong correlation between ambient air pollution and COVID-19 cases, which has affected the lives of billions of people around the world. Abatement technologies such as ionic and other high efficiency filtration systems are quite expensive and hence unaffordable to communities with limited resources. The goal of this study was to develop an air pollution filtration method utilizing selective nanoparticle deposition in optimized concentrations, to maximize the entrapment of PM2.5 particles. The experimental set-up consisted of a wind tunnel with incense sticks as the PM2.5 source, measured by laser particle detectors upstream and downstream of the filters. Different nanoparticle coated filters were tested using the ‘Design of Experiments’ methodology and it was concluded that an optimized mixture of zinc oxide, titanium dioxide & graphene improved filtration efficiency of a baseline filter by 206% and was 70% cheaper than high efficiency filters. The versatility and cost-effectiveness of this design makes it applicable for personal masks & filters, air-conditioning and car-cabin filters, and fire-fighting equipment. The significant correlation between air pollution and fatalities from viral infections like COVID-19, makes such abatement technologies with innovative filtration systems critical to save human lives.
{"title":"Air pollution abatement by selective nanoparticle deposition on filtration systems","authors":"Ishika Nag","doi":"10.17159/caj/2022/32/1.11389","DOIUrl":"https://doi.org/10.17159/caj/2022/32/1.11389","url":null,"abstract":"Air pollution kills an estimated seven million people worldwide every year. The data from the World Health Organization (WHO) shows that almost all the global population (99%) breathe air that exceeds WHO guideline limits. The growing population and urbanization such as in Africa, which has the fastest growing population, may lead to substantial worsening of the air quality. Urbanization is also a powerful driver of the epidemiologic transition from traditional threats like infectious diseases and malnutrition to chronic, non-communicable diseases. Particulate matter less than 2.5 microns in size, PM2.5, is the leading contributor to air pollution which results in such diseases like chronic obstructive pulmonary disease (COPD), bronchitis, and lung cancer. Recent studies have shown a strong correlation between ambient air pollution and COVID-19 cases, which has affected the lives of billions of people around the world. Abatement technologies such as ionic and other high efficiency filtration systems are quite expensive and hence unaffordable to communities with limited resources. The goal of this study was to develop an air pollution filtration method utilizing selective nanoparticle deposition in optimized concentrations, to maximize the entrapment of PM2.5 particles. The experimental set-up consisted of a wind tunnel with incense sticks as the PM2.5 source, measured by laser particle detectors upstream and downstream of the filters. Different nanoparticle coated filters were tested using the ‘Design of Experiments’ methodology and it was concluded that an optimized mixture of zinc oxide, titanium dioxide & graphene improved filtration efficiency of a baseline filter by 206% and was 70% cheaper than high efficiency filters. The versatility and cost-effectiveness of this design makes it applicable for personal masks & filters, air-conditioning and car-cabin filters, and fire-fighting equipment. The significant correlation between air pollution and fatalities from viral infections like COVID-19, makes such abatement technologies with innovative filtration systems critical to save human lives.","PeriodicalId":37511,"journal":{"name":"Clean Air Journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46021924","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-24DOI: 10.17159/caj/2022/32/1.14070
B. Wernecke, Kristy E. Langerman, R. Garland, G. Feig
Background On 18 March 2022, the Pretoria High Court found that chronic air pollution is a violation of Section 24 of the South African Constitution, and that South Africans have a right to an environment that is not harmful to their health and well-being (CER, 2022). This “has important implications for communities forced to live with the debilitating effects of air pollution on the Mpumalanga Highveld, and more broadly for constitutional jurisprudence and government accountability” (CER, 2022).
{"title":"Ambient air pollution on the Highveld: An airshed at a watershed moment?","authors":"B. Wernecke, Kristy E. Langerman, R. Garland, G. Feig","doi":"10.17159/caj/2022/32/1.14070","DOIUrl":"https://doi.org/10.17159/caj/2022/32/1.14070","url":null,"abstract":"Background On 18 March 2022, the Pretoria High Court found that chronic air pollution is a violation of Section 24 of the South African Constitution, and that South Africans have a right to an environment that is not harmful to their health and well-being (CER, 2022). This “has important implications for communities forced to live with the debilitating effects of air pollution on the Mpumalanga Highveld, and more broadly for constitutional jurisprudence and government accountability” (CER, 2022).","PeriodicalId":37511,"journal":{"name":"Clean Air Journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42161846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-17DOI: 10.17159/caj/2020/31/2.12811
B. Wernecke
A three-hour, flash presentation series was organized for students in the boarder research area of air quality. A total of 18 students from the Environmental Science & Engineering Department, Aerospace Engineering Department, Chemical Engineering Department, Centre for Urban Science & Engineering and Interdisciplinary Program in Climate Studies participated in this event. They presented their ongoing research in 5-7 minute long presentations that were followed by a discussion panel. The topics were diverse and ranged from characterization of emissions sources, low-cost monitoring, air quality modelling, environmental justice and indoor air quality. The three house session saw 40-50 attendees. All participants actively interacted in the panel discussions and helped towards capacity building by identifying knowledge sources and resources in the larger peer group.
{"title":"Clean Air Journal celebrated this year’s International Day of Clean Air for Blue Skies","authors":"B. Wernecke","doi":"10.17159/caj/2020/31/2.12811","DOIUrl":"https://doi.org/10.17159/caj/2020/31/2.12811","url":null,"abstract":"A three-hour, flash presentation series was organized for students in the boarder research area of air quality. A total of 18 students from the Environmental Science & Engineering Department, Aerospace Engineering Department, Chemical Engineering Department, Centre for Urban Science & Engineering and Interdisciplinary Program in Climate Studies participated in this event. They presented their ongoing research in 5-7 minute long presentations that were followed by a discussion panel. The topics were diverse and ranged from characterization of emissions sources, low-cost monitoring, air quality modelling, environmental justice and indoor air quality. The three house session saw 40-50 attendees. All participants actively interacted in the panel discussions and helped towards capacity building by identifying knowledge sources and resources in the larger peer group.","PeriodicalId":37511,"journal":{"name":"Clean Air Journal","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48710311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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